Crossover Point between Dialkoxy Disulfides (ROSSOR) and Thionosulfites ((RO)<sub>2</sub>SS): Prediction, Synthesis, and Structure
作者:Eli Zysman-Colman、Neysa Nevins、Nicolas Eghbali、James P. Snyder、David N. Harpp
DOI:10.1021/ja0559395
日期:2006.1.1
Isomeric preference between cyclic dialkoxy disulfides and thionosulfites is governed by the ring size of the heterocycle. Rings smaller than seven atoms prefer the thionosulfite connectivity, whereas larger rings or acyclic analogues favor the unbranched dialkoxy disulfide structure. Density functional calculations were employed to predict the crossover point at which both constitutional isomers are of comparable stability. Follow-up synthesis provides the previously unknown eight-membered ring dialkoxy disulficle 14 and seven-membered ring thionosulfite 15 from the same reaction. X-ray crystallography for all but one of the reaction products and complementary NMR analysis furnishes insights into both solid-state and solution conformations. A long-standing issue regarding the concerted vs catalyzed isomerization pathway between XSSX and X2S = S has been addressed for X = RO and shown to be acid dependent.
Investigation of Sulfur Extrusion from a Cyclic Dialkoxy Disulfide
作者:Nicolas Eghbali、David N. Harpp
DOI:10.1021/jo062190n
日期:2007.5.1
been examined. Investigations demonstrate an interconversion between thionosulfite 12 and sulfoxylate 13. This sequential transformation brings evidence that a branched-bond sulfur structure is likely involved in sulfurextrusion.